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' ELECTRIC CONDUCTOR;

8- Patented Oct. 23, 1883.

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I (No Model.) '3 Sheets-Sheet 2 I 1 ELECTRIC CONDUCTOR. v i No. 287,288. I Patented 001;. 28,1888.

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UN TED STATES PATENT OFFICE; I

FRANK JACOB, OFWOOLWIOH, COUNTY or KENT, ssienou; To, j SIEMENS BROTHERS -& COMPANY, (LIMITED,) or WESTMINSTER,"ENGLAND.

ELECTRIC CONDUCTOR.

SPECIFICATION forming part of Letters Patent No.. 287,288, dated October 23,1883,

. Application med Mav2,1883. (No model.) Patented a England January 11, nee-a. No.21, and July 1l.188-2.N-o.3,2$1.

in Germany July 14. 1882, No. 21,824, and in France July 15, 1882, No. 150,114.

To all whom/it may concern.- I

Be; it known that I, FRANK JACOB, acitizcn of England, residing atWoolwich, in the county of Kent, England, have inventeda-riew 5 and useful Improvement in Electric Conductors, (forwhich Letters Patont'have been obtained in Great Britain, dated January 17, 1882, I and dated 'Julyll, 1882, No. 3,281; a in France dated Jul 15, 1882, No. 150,114, and a in Germany dated uly 14,1882, No. 21, 824,) of which the following is a specification. It is oiten of great advantage. to employ for electrical purposes pairs of conductors, the one of each pair leadingthe currents to a dis-.

5 tant instrument. or apparatus and the other serving'for the return-currents. .When the. electricity is employed to work telephonic instrnment's, it is particularly advantageous to. employ in this manner pairs of wires and to twine them together in one cord, as this hasthe effect of preventing interference by induction from adjacent wires, On the other hand,- when there are many sets of instruments or apparatus requiring electrical conductors, the

5 doubling of their respective wires involves considerably increased expense, and therefore recourse is generally 'had to the use of the earth, instead of a return-wire, thus saving cost, but in many cases sacrificing efficiency.

Now, the object of my invention is to secureall' ;the advantages of duplicate conductors without incurring: the double expense which their use involves, and this I eifect by the system which I will now describe.

1 will assume that there is a double wire provided for telephonic or telegraphic conduetion to and from one distant instrument, which I may call A, and also a double wire .following the same course fora second instru- .o ment, B. :According to myinvention, Iwork a third instrument, without any additional 'wire bysimply using the double wires of the first and second instruments to com letethe circuit for the third the-one pair 0 wires-'- 5 say those for the first instrument, A-conducting'the currents to the third instrument, 0, and the other pain-namely, those for the 'second-instrument,B-cbmlubting the currents back from the third. Again, if there were 0 four as: ments, A, B, D, and E, each having its pair of wires, the-pair-for B may serve .i'or another,-C, as

, formingpart of, another circuit; A each pair or combined set. ofwi-rcs may be then the pair for A and above described; also,='the pairfcr Bend the pair for'E may similarly serve foranother instrument, F. Not" only so, but the four wires 5 so applied forv G and the four wires forF may serve for another 1 instrument, G, the result being that seveninstrum'entsare worked by eight wires. QBysimilarly multiplying instru= ments, I amenabled 'to work approximately one instrument for each wire, retaining, nevertheless, for each instrument a pair of conductor'sr r In cases where the earth may, without serious objection, be used instead of the returnwire, the conductors may be somewhat diiierently combined., Thusan instrument, H, mayhave its doublewire, and these twofwires',

with earth for return, may work anotherfiinstrument, I; or, again, two instrumentse -such as H and J- may-have" each its-. pair of wires. The wires of H and earth may be used for K,

and the wires of J and earth may be used for L;- or the two pairs of wires fonH and J may. form a complete circuit for M, and the four wires, with earth 'for. return, may; serve for N, thus providing as many circuits as there are wires;

It isobvious that many -other' combinations might be formedin thist'm'anner, all following the same system-'that isto say, whenever 8o two wires are used in completing-a single circuit, that-"pair may be used as a sin%le .line though thus made to serve in several distinct circuits,

the instruments of those circuits can never thel'e'ss be operated "simultaneously without interfering with one another, as may be understood by considering the condition of the A, B, and O circuits above describedas the first illustrationof the application of my system;

I will suppose-that the A'circuitis in use, an

electrical current passing forward along one of its wires and returning by the other, and that at thi's'time the G circuitis brought into use by a current passingbforward along the A pair ofwires and back y the B air. The-efifect ofthis additional current ma es no difi'erence in the relative condition of the two A wires, for

bywhatever positive potential it may increase 10 before, and therefore the effect on the instruments operated by them is unchanged. In like manner when a greater number of circuits are connected, as above described, each circuit remains unintluenced by currents passing through both its wires to serve other circuits. In circuits thus connectedthe non-interference of each pair of instruments with the others is effected by bridgeconnections-with rcsistancesor condensers, or combinations of these. As an example of this arrangement, I

. may refer to Figure 1, in which two instruments or apparatus, A and A, are connected together by a double line of wires, L. Two other instruments, B and B, may be connected together in themanner indicated by a conductingline madeup'of the single portions! 1 (which may be of any length) and of the double line L, the cart being used for return.- The con ductors are arranged to'form abridge for each of the instruments A A with resistances R or condensers, or both, in the, limbs of the bridge, so as to determine equality of potential on each side oi A and A. Fig. 2 illustrates my system of connecting for four pairs of instruments. Two pairs, A A and A A, are'connected by their .double wires L L. These double wires form the circuit for a-pair, O ,0, and the four wires of L and L, with earth for returmform the circuitforthe fourth pair,D D.

Figs.'3, i, and 5 illustrate various ways of connecting dili'erentkinds of instruments at one of the stations, similar connections being made in each case at the other'station'. Fig. 3 illnstra s the connections for ordinary diroot-working Morse recorders or sounders. A

works through the complete circuit of the,

lines L L, B works through D L, together with earth for return, the balance being eflected by properly-adjusted resistances "R B. Fig. 4 illustrates connections for single needle or galvanometer reflecting-instruments, the balance being effected by condensers G O. The condenser C" may be used or not as in the ordinary working of submarine cables' The switches S S serve, as usual, to connect the line to the sending-key or to the receiving-instrurncnt.' In Fig. 5 a magnetic telephone, A, is on the complete circuit L L, and an ordinary Morse instrument, B, is worked through L L as one line, with earth'for return, the balance being effected by a combination of resistances and condensers at M M and m.

i Fig. 6 illustrates the method applied to five lines so as to work four pairs of instruments without materal interference. The lines 1 2 form complete circuit for duplex Morse instruments, A having the artificial line a. The

resistance's'and condensers at M M.

lines 3 4 form complete circuit for magnetic telephone B. Thelines 1 2 form one conductor and 3 4 form the other conductor for Hughes type-printers'O, the balance on 1 2 being ob tained by resistances R, and the balance on 3 4 by duplex casting of B. .By 1, 2, 3, and 4 together as. one line, and 5 as the other, there is a complete circuit for single needle or mirror instruments D, having switches S for connecting line to sending-key or to receiving-instrument in the usual way. The balance isin this case effected by condensers Q. Finally, with the five wires altogether as one line, and earth for return, relays E work local sounders, the balance being eflccted'by a combination of The balance at'the two-ends of a pair of lines may be obtained by different means. For example, rcsistances may be used at the one end and condensers at the other; or differentcombinations of these may be used at each end. 1

Three stations may be connected, as illustrated by Fig. 7, in which telephones X are worked by 1 2' in complete circuit, and the points A and B are connected 'to relays Y, working local Morse instruments, either or both of these being at a distance, as indicated at 0, connected to B by a single line.

Having thus described the nature of my invention and the best means I know of carrying it into practical effect, I claim- 1. The within-described improvement in tele graphic circuits, which consists in the combination of double connecting-lines joining two stations, each of said double lines constituting a complete or distinct wire circuit in itselfi'and both together an independent direct or earth circuit, whereby said circuits may be utilized for two or more distinct sets of instruments.

2. At each end of a double or multiple line consisting of two ,or more conductors which connect in complete circuit an electrical instrument or apparatus at one station with au'instrument or apparatus at another station, the

A combination therewith of an additional instrument or apparatus with a bridge-connection and resistance, or the equivalents thereof, wherebythe'said double or multiple line is made to serve as a single connecting-line for the additional instruments or apparatus without interfering with those for which it forms the complete circuit, substantially as and for the purposes set forth.

In testimony whereof I have signed my name 'to this specification, in the presence of, two

subscribing witnesses, this 13th day of April,

' FRANK JACOB Witnesses:

JOHN 'LURAYM JNO. P. M. MILLARD.

Correction in Letters Patent No. 287,288.

It is hereby certified that in Letters Patent No. 281,288, grztnted October 23, 1883,

upon'the applicttion of Frank J acob, of Wor'mlwich, county of Kent, England, for an improvement in Electric Conductors, errors appear in the printed specification requiring correction, as follows a In line 60, page 2, the word maleral should read mutual;

in 1ine'68, same page,- the word casting should read coiling and the name of one Of the witnesses to the specification should read Jolm Immy instead of John Lmyw and that the proper corrections have been made in the files and records pertaining to the case in the Patent Officc, and should he read in the letters patent to make it conform thereto. 7 v Q I V I Signed, conntersigned, and sealed thishtl day of Fcbrnory, A. 1884.

[SEAL] M. L. JO SLYN, v

Acting Secretary of the Interior. Countersigned: 

